Adjusting device for the tightness of the knitting on knitting machines

ABSTRACT

Knitting machine needle cam adjusting arrangements wherein a transport nut is moved along a shaft which is turned by a motor which also moves a potentiometer element forming a part of a bridge circuit which controls the motor to one of several optionally selectable positions. The transport nut is arranged to engage a stop on which a spring biased needle cam is mounted, to set the cam position.

United States Patent Krause Nov. 13, 1973 ADJUSTING DEVICE FOR THETIGHTNESS [5 6] References Cited OF THE KNITTING ON KNITTING UNITEDSTATES PATENTS MACHINES 1,571,765 2/1926 Felsl 66/75 [75] Inventor;Erich Krause Bopfingen Ge -many 3,035,426 5/1962 Maqueen 66/76 [73]Assignee: Universal Maschinenfabrik Dr. Primary Examiner Ronald FeldbaumRudolf Schleber Att0rneyJ0seph M. Fitapatrick et a].

Westhausen, Germany [22] Filed: Jan. 31, 1972 57 ABSTRACT PP 222,067Knitting machine needle cam adjusting arrangements wherein a transportnut is moved along a shaft which [30] Foreign Application Priority Datais turned by a motor Wl'llCh also moves a potentiometer element forminga part of a bridge circuit WhlCl'l Mar. 10, 1971 Germany t. P 21 ll553.7 controls the motor to one of Several optionally Se]ecta [52] U SCl 66/78 ble positions. The transport nut is arranged to engage n I s sI s 1 u a on a S rin cam 51] Int. CL... D04b 7/00, D04b 15/36, D 0i1 3 5/9 9 mounfed to set the campposgition [58] Field of Search 66/77, 78, 76

6 Claims, 4 Drawing Figures 2| @111111111 llr-ill 1/ lo 1k 22 A I, H 33i r"- J V A PATENTEnnuv 13 I975 3.771, 329

SHEET 2 BF 2 l: z /A ADJUSTING DEVICE FOR THE TIGHTNESS OF THE KNITTINGON KNITTING MACHINES The present invention relates to a device foradjusting the tightness of knitting produced on knitting machines, andparticularly flat-bed knitting machines, by changing the position of theknitting machines stitch cams.

In known flat-bed knitting machines the tightness of knitting isadjusted by means of a device of complicated construction provided onthe carriage which carries the stitch cams of the machine. The heavyelements of this adjustment device must continuously be moved togetherwith the carriage. In known adjustment devices, wherein a selectedstitch cam is shifted in position by means of shift bolts, guidance ofthe stitch cam presents particularly great difficulties. Since the placefor the adjustment of the device must be readily accessible, the shiftbolts rest via setting tabs on the surface of the carriage and musttransmit the value set to the cam stitch present above the needle bed.Since the shiftable bolts lie in between, the transmission of movementis both difficult and inaccurate. An indication for the reading of theposition must furthermore be arranged in a readily visible place,whereby further difficulties in construction and movement transmissionresult.

It is an object of the present invention to provide a device foradjusting the position of a stitch cam which does not have thedisadvantages indicated above and which makes possible an easy andaccurate transmission of a preselected position of the stitch cams.

This object is obtained, in accordance with the present invention, bymeans of an electrically controlled or regulated electric motor which isarranged to effect displacement of the stitch cams.

In one suitableembodiment of the invention the adjustment devicecomprises a continuously operating electric motor for adjustment of thestitch cams and an electric bridge circuit including an electricdisplacement pickup and at least one individually adjustable electricsetting device by means of which the electric motor is controlled.

The electric setting devices may be potentiometers mounted in aconveniently accessible location. The electric displacement pickup ispreferably firmly connected to the stitch cam. The adjustment device ofthe present invention is preferably so developed that the differentelectric setting devices are automatically connected in optionallycontrollable manner with the control apparatus of the knitting machine.

Apparatus according to the present invention can be so constructed thatthe stitch cam together with its entire adjustment device is supportedin such a manner that it can be moved upward against spring action in alock in a vertical direction by the needle butts of the knitting machineneedles. The adjusting device comprises in this connection, forinstance, means supporting and guiding of the stitch cam, an adjustingspindle, a displacement pickup and an electric motor.

One advantage of the apparatus in accordance with the invention residesin the fact that the adjusting devices are no longer contained on thecarriage, while the electric motor itself together with itscorresponding measuring and actuating means is arranged on the carriage.

There has thus been outlined rather broadly the more important featuresof the invention in order that the detailed description thereof thatfollows may be better understood, and in order that the presentcontribution to the art may be better appreciated. There are, of course,additional features of the invention that will be described hereinafterand which will form the subject of the claims appended hereto. Thoseskilled in the art will appreciate that the conception upon which thisdisclosure is based may readily be utilized as a basis for the designingof other structures for carrying out the several purposes of theinvention. It is important, therefore, that the claims be regarded asincluding such equivalent construction as do not depart from the spiritand scope of the invention.

A specific embodiment of the invention has been chosen for purposes ofillustration and description, and is shown in the accompanying drawings,forming a part of the specification, wherein:

FIG. 1 is a schematic wiring diagram for a stitch cam adjustment deviceaccording to one embodiment of the present invention;

FIG. 2 is a schematic top view of a removeable part of an adjustmentdevice according to the present invention and showing a control andmeasuring unit for the positioning of a stitch cam;

FIG. 3 is a top view of an adjusting knob with a vernier scale, formaking adjustments to the circuit of FIG.

FIG. 4 is a view, partially in section, of an adjusting device inaccordance with the present invention, and showing that device in itsupward position.

As shown in the wiring diagram of FIG. I, there is provided a bridgecircuit 9 for supplying current to a continuously operating electricmotor for the displacement of stitch cams. One half of the bridgecircuit 9 comprises one of four manually adjustable selectionpotentiometers l, 2, 3 and 4 which are arranged in easily accessiblefashion on the main body of the knitting machine. Each of thepotentiometers l, 2, 3 or 4 can be connected optionally into the bridgecircuit 9 by means of a switch 5, 6, 7 or 8 associated with it. Theswitches 5, 6, 7 and 8 are located in the control apparatus of theknitting machine and are, if necessary, automatically selected andactuated. The remaining half of the bridge circuit 9 comprises adisplacement pickup 10 which is, for instance, also a potentiometer andis connected with the connected selection potentiometer l, 2, 3 or 4 tocomplete the bridge. The bridge circuit 9 is fed by a source of voltage9a.

The displacement pickup 10 which, as is shown in FIG. 2, is firmlyconnected with the stitch cam 11, is displaced by the rotation of amotor 12 which is controlled via an amplifier 13 corresponding to thedetuning of the bridge circuit 9. The motor 12 rotates in a givendirection until equalization of voltage has been obtained in the bridgecircuit 9 corresponding to the adjustment of the potentiometer l, 2, 3or 4 connected at the time.

As can be noted from FIG. 2, the stitch cam isguided in a cam plate 14,and is pulled firmly by a tension spring 15 via a stop 16 against atransport nut 17. The transport nut 17 travels on an adjustment spindle18 which is lightly supported in bearings 19 and 20. A bevel gear 22,firmly connected with the adjustment spindle 18, is driven by a bevelgear 21 which is firmly seated on the shaft of the motor 12 so that,depending on the direction of the rotation of the motor 12, thetransport nut 17, and thus the stitch cam 11, is moved up or down. Thedisplacement pickup is rigidly connected with the stitch cam 11 so thatit indicates the exact position thereof.

The potentiometers l, 2, 3 and 4 are each adjusted by means ofindividual rotary knobs 24 bearing a vernier scale 23, as shown in FIG.3. The rotary knobs for this adjustment are arranged on the main frameof the knitting machine at a place which is readily accessible.

In FIG. 4 there is shown a view, partially in section, of the adjustingdevice in accordance with the invention. Since upon the knitting theleading stitch cam must always be swung so high that it does not pullthe needles down below cam level, it would be disadvantageous if thestitch cam had to move over a large distance at each point of reversalof the carriage and if its displacement time differed from the actualadjustment time. The entire adjusting device 24 is therefore fastened totwo guide bolts 27 and 28 which are guided in the carriage 26 and arepulled downwardly by a spring 29 at all times in the direction of anarrow A shown in FIG. 4. It remains in this position if the stitch camlags, i.e. when it pulls down the needles for the stitching. At thepoint of reversal of the carriage the adjusting device is pressed by aninclined surface (not shown) in the direction opposite that of the arrowA shown in FIG. 4, and an electromagnet 30 shifts a detent bolt 31 intoa detent groove 32 in the guide bolt 28. The entire adjusting device isso held that the switch cam 11 can no longer reach a needle butt 33. Bythis lifting it is possible to effect a new displacement of the stitchcam 11 for the corresponding adjustment of the tightness of the knittingduring the stroke of the carriage during which the stitch cam leads.

Having thus described the invention with particular reference to thepreferred form thereof, it will be obvious to those skilled in the artto which the invention pertains, after understanding the invention, thatvarious changes and modifications may be made therein without departingfrom the spirit and scope of the invention, as defined by the claimsappended hereto.

What is claimed is:

1. Apparatus for adjusting the tightness of the knitting by changing theposition of the stitch cams on knitting machines, such as flat-bedknitting machines, said apparatus comprising an electric motor mountedadjacent to a stitch cam to be adjusted and said motor being coupled tosaid cam to adjust the position thereof, and an electric motor controlcircuit for controlling the operation of said motor to adjust said camto a predetermined position, said control circuit comprising an electricbridge circuit, said bridge circuit including, on one side thereof, anelectric displacement pickup firmly connected with the stitch cam, andon the other side, at least one individually adjustable electric settingdevice via which the electric motor can be controlled.

2. Apparatus according to claim 1, by the fact that the electric settingdevices are otentiometers.

3. Apparatus according to claim 1 wherein the electric displacementpickup is rigidly connected with the stitch cam.

4. Apparatus according to claim 1, wherein the electric setting devicesare connectable in automatically optionally controlled manner with thecontrol apparatus of the knitting machine.

5. Apparatus according to claim 1, wherein there is provided supportingmeans by which the entire adjusting device, including said stitch cam,is supported vertically under spring action in a carriage lock in such amanner that it can be moved upward by the needle butts.

6. Apparatus according to claim 5, wherein said supporting meansincludes guide elements mounted to permit the stitch cam to be adjustedupon movement of the adjusting device to an upward position.

UNITED STATES PATENT OFFICE I, I CERTIFICATE OF. CORRECTION Patent No 3771,329 Dated November 13 1973 Inventor) ERICH KRAUSE It is certifiedthat error appears in the above identifie d pat ent and that saidLetters Patent are hereby corrected as shown below:

Title page I Column 1, item [731 delete "G. m .b.H."

and substitute --KG-. Signed and sealed this 9th day of July 197 (SEAL)V Attest:

I c. MARSHALL DANN MccQr lg I. GIBSON IR. I Attesting Officer 5Commissioner of Patents FORM PO'IOSO 0'59,

1. Apparatus for adjusting the tightness of the knitting by changing theposition of the stitch cams on knitting machines, such as flat-bedknitting machines, said apparatus comprising an electric motor mountedadjacent to a stitch cam to be adjusted and said motor being coupled tosaid cam to adjust the position thereof, and an electric motor controlcircuit for controlling the operation of said motor to adjust said camto a predetermined position, said control circuit comprising an electricbridge circuit, said bridge circuit including, on one side thereof, anelectric displacement pickup firmly connected with the stitch cam, andon the other side, at least one individually adjustable electric settingdevice via which the electric motor can be controlled.
 2. Apparatusaccording to claim 1, by the fact that the electric setting devices arepotentiometers.
 3. Apparatus according to claim 1 wherein the electricdisplacement pickup is rigidly connected with the stitch cam. 4.Apparatus according to claim 1, wherein the electric setting devices areconnectable in automatically optionally controlled manner with thecontrol apparatus of the knitting machine.
 5. Apparatus according toclaim 1, wherein there is provided supporting means by which the entireadjusting device, including said stitch cam, is supported verticallyunder spring action in a carriage lock in such a manner that it can bemoved upward by the needle butts.
 6. Apparatus according to claim 5,wherein said supporting means includes guide elements mounted to permitthe stitch cam to be adjusted upon movement of the adjusting device toan upward position.